feat(shell): Add an action to cache it

.forgejo/workflows/eval-shell.yaml

@@ -0,0 +1,19 @@
+jobs:
+  build-shell:
+    runs-on: nix
+    steps:
+    - uses: actions/checkout@v3
+    - env:
+        STORE_ENDPOINT: https://tvix-store.dgnum.eu/infra-signing/
+        STORE_PASSWORD: ${{ secrets.STORE_PASSWORD }}
+        STORE_USER: admin
+      name: Build and cache shell
+      run: nix-shell -A eval-shell --run "nix-cache -A devShell"
+name: Build the shell
+on:
+  pull_request:
+    branches:
+    - main
+  push:
+    branches:
+    - main

default.nix

@@ -180,6 +180,7 @@ in
       pre-commit.shellHook = git-checks.shellHook;
       check-workflows.shellHook = workflows.shellHook;
       eval-nodes.packages = [ scripts.cache-node ];
+      eval-shell.packages = [ scripts.nix-cache ];
     };
   };
 }

scripts/default.nix

@@ -21,6 +21,7 @@ let
 
   scripts = {
     cache-node = [ colmena ];
+    nix-cache = [ colmena ];
     check-deployment = [
       colmena
       jq

scripts/nix-cache.sh

@@ -0,0 +1,29 @@
+# SPDX-FileCopyrightText: 2024 Ryan Lahfa <ryan.lahfa@dgnum.eu>
+# SPDX-FileCopyrightText: 2024 Tom Hubrecht <tom.hubrecht@dgnum.eu>
+# SPDX-FileContributor: Maurice Debray <maurice@dgnum.eu>
+#
+# SPDX-License-Identifier: EUPL-1.2
+
+# Build the derivation and send it to the great beyond
+
+drv=$(nix-instantiate "$@")
+nix-store --query --requisites --force-realise --include-outputs "$drv" | grep -v '.*\.drv' > paths.txt
+
+if [ "$STORE_PASSWORD" == "" ]; then
+  echo "No password given for the remote cache, uploading cannot take place."
+  exit 0
+fi
+
+cat <<EOF >.netrc
+default
+login $STORE_USER
+password $STORE_PASSWORD
+EOF
+
+nix copy \
+  --extra-experimental-features nix-command \
+  --to "$STORE_ENDPOINT?compression=none" \
+  --netrc-file .netrc \
+  "$(nix-store --realise "$drv")"
+
+rm .netrc

workflows/eval-shell.nix

@@ -0,0 +1,29 @@
+# SPDX-FileCopyrightText: 2024 Tom Hubrecht <tom.hubrecht@dgnum.eu>
+#
+# SPDX-License-Identifier: EUPL-1.2
+
+{
+  name = "Build the shell";
+  on = {
+    pull_request.branches = [ "main" ];
+    push.branches = [ "main" ];
+  };
+
+  jobs = {
+    build-shell = {
+      runs-on = "nix";
+      steps = [
+        { uses = "actions/checkout@v3"; }
+        {
+          name = "Build and cache shell";
+          run = "nix-shell -A eval-shell --run \"nix-cache -A devShell\"";
+          env = {
+            STORE_ENDPOINT = "https://tvix-store.dgnum.eu/infra-signing/";
+            STORE_USER = "admin";
+            STORE_PASSWORD = "\${{ secrets.STORE_PASSWORD }}";
+          };
+        }
+      ];
+    };
+  };
+}